The invention relates to combustors for gas turbine engines assembled of an inner and an outer combustor wall with heat shields mounted internally. The combustor walls overlap at the annular dome portion of the combustor which also contains nozzle openings, impingement air cooling openings and openings to permit heat shield fasteners to pass through. The heat shield fasteners can also serve to clamp together the overlapping portions thereby sealing the overlapping surfaces.
An example of such a combustor is described in U.S. Pat. No. 6,497,105 to Stasny.
As the size of the overlapping portions increases, the likelihood of maintaining the seal increase, however interference with openings in the dome for cooling airflow and fuel nozzles increases. Since gas turbine engines and their combustors are assembled or stacked up from many interengaged parts, the compounding effect of manufacturing tolerances for each component results in a cumulative lack of accuracy for the assembled combustor. Small but allowable variations in dimensions within the tolerances set for manufacture, add up to result in a variation in the dimensions and locations of components in the assembled combustor.
Features that distinguish the present invention from the background art will be apparent from review of the disclosure, drawings and description of the invention presented below.